血管紧张素Ⅱ对小鼠足细胞小窝蛋白1表达的影响

目的 观察血管紧张素Ⅱ（AngⅡ）刺激及氯沙坦干预对足细胞小窝蛋白1（caveolin-1）表达的影响,探讨caveolin-1在足细胞损伤中的作用.方法 体外培养永生化小鼠足细胞（MPC）,AngⅡ（10-6mol/L）刺激不同时间（3 h、6h、12 h和24 h）;Losartan（10-6 mol/L）提前预处理3h后与AngⅡ（10-6 mol/L）共孵育6h,Hoechst-33342检测足细胞凋亡率,Western-blot法检测各组细胞caveolin-1蛋白表达,免疫荧光检测caveolin-1及其磷酸化水平.结果 ①AngⅡ刺激3h,足细胞即开始发生凋亡,随着刺激时间的延长,足细胞凋亡明显增多（P＜0.05）.②AngⅡ刺激不同时间caveolin-1表达总量无明显改变（P＞0.05）,从3h开始,caveolin-1磷酸化水平明显增高（P＜0.05）.③Losartan干预后caveolin-1磷酸化水平明显降低（P＜0.05）.结论 caveolin-1可能在AngⅡ诱导的足细胞损伤中发挥着重要的作用.     

New insights into human minimal change disease: lessons from animal models

The pathogenesis of minimal change disease (MCD), considered to be the simplest form of nephrotic syndrome, has been one of the major unsolved mysteries in kidney disease. In this review, recent landmark studies that have led to the unraveling of MCD are discussed. A recent study now explains the molecular basis of major clinical and morphologic changes in MCD. Overproduction of angiopoietin-like 4 (ANGPTL4) in podocytes in MCD causes binding of ANGPTL4 to the glomerular basement membrane, development of nephrotic-range selective proteinuria, diffuse effacement of foot processes, and loss of glomerular basement membrane charge, but is not associated with changes shown by light microscopy in the glomerular and tubulointerstitial compartments. At least some of this ability of ANGPTL4 to induce proteinuria is linked to a deficiency of sialic acid residues because oral supplementation with sialic acid precursor N-acetyl-d-mannosamine improves sialylation of podocyte-secreted ANGPTL4 and significantly decreases proteinuria. Animal models of MCD, recent advances in potential biomarkers, and studies of upstream factors that may initiate glomerular changes also are discussed. In summary, recent progress in understanding MCD is likely to influence the diagnosis and treatment of MCD in the near future.     

Repair problems in podocytes: wnt, notch, and glomerulosclerosis

Wnt/Ctnnb1 and Notch signaling play key roles in kidney development and epithelial cell specification. Recent reports have suggested that these pathways are reactivated in response to injury and in different disease conditions. Studies using genetically modified animal models showed that sustained activation of Notch and Wnt signaling in podocytes are causally related to albuminuria and glomerulosclerosis development. Here, we discuss the role and regulation of Wnt/Ctnnb1 and Notch signaling in podocytes.     

Signaling from the podocyte intercellular junction to the actin cytoskeleton

Observations of hereditary glomerular disease support the contention that podocyte intercellular junction proteins are essential for junction formation and maintenance. Genetic deletion of most of these podocyte intercellular junction proteins results in foot process effacement and proteinuria. This review focuses on the current understanding of molecular mechanisms by which podocyte intercellular junction proteins such as the nephrin-neph1-podocin-receptor complex coordinate cytoskeletal dynamics and thus intercellular junction formation, maintenance, and injury-dependent remodeling.     

方格星虫提取物对膜性肾病模型的治疗作用及机制初探

目的:初步探讨方格星虫粗提物(SNP)对膜性肾病(MN)的治疗作用及其可能机制。方法:50只SD大鼠随机分为模型组和对照组,模型组大鼠腹腔一次注入抗FxlA血清建立被动性Heymann肾炎模型,模型建立1周后依24 h尿蛋白排泄量(24 h UPE)随机将Heymann肾炎大鼠分为SNP治疗组和未治疗组,治疗组用SNP灌胃治疗。考马斯亮蓝法每周测定24 h UPE。治疗4周结束后处死大鼠取双肾,光镜、电镜观察肾脏病理改变,RT-PCR法检测肾组织nephrin mRNA和podocin mRNA的表达量。结果:SNP治疗4周后大鼠24 h UPE较未治疗组降低(P<0.05);模型组大鼠肾小球基底膜增厚,上皮下电子致密物沉积,足细胞足突融合等病理改变,SNP治疗组大鼠上述病变较未治疗组减轻,经测定,足细胞足突融合率较未治疗组显著降低(P<0.01);SNP治疗组nephrin mRNA和podocin mRNA表达量较未治疗组升高(P<0.05)。结论:SNP可通过上调膜性肾病大鼠足细胞nephrin和podocin基因表达水平,一定程度上减轻足细胞足突融合,进而减少尿蛋白滤过,可能对人类膜性肾病具有辅助治疗作用。     

叉头状转录因子O1对糖尿病大鼠足细胞影响的实验研究

目的 探讨叉头状转录因子O1（Fox01）对糖尿病大鼠足细胞的影响.方法 链脲佐菌素（STZ）诱导构建糖尿病大鼠模型90只,并采用简单随机抽样法分为糖尿病（DM）＋空慢病毒载体（LV-pSC-GFP）感染组（LV-NC组,n=30）,DM＋大鼠结构性活性FoxO1慢病毒载体（LV-CA-FoxO1）感染组（LV-CA组,n=30）,DM组（n=30）,另设对照组（NG组,n=30）注射相应体积的柠檬酸钠-柠檬酸缓冲液.于慢病毒感染后的2、4、8周末,测大鼠尿白蛋白、体重、血糖、血肌酐、尿素氮,光镜和透射电镜观察肾小球及其足细胞结构变化,实时定量聚合酶链反应（RT-PCR）和Western blotting法检测大鼠肾皮质中FoxO1、足盂蛋白（PCX）、nephrin mRNA和蛋白的表达.多组间比较采用单因素方差分析.结果 与LV-NC、DM组相比,LV-CA组大鼠肾脏中FoxO1 mRNA、蛋白表达水平明显升高（F8W值分别为10 919.75、3 867.34,均P＜0.05）,尿白蛋白、血肌酐、尿素氮明显降低（2周除外）（F8W值分别为132.72、187.68、503.69,均P＜0.05）,肾脏中PCX、nephrin mRNA和蛋白水平明显升高（mRNA F8w值分别为778.94、478.10;蛋白F8W值分别为393.64、255.79,均P＜0.05）,肾脏病理学变化也明显改善,可见肾小球体积减小,系膜细胞及基底膜增生程度降低,足突融合也有一定程度改善.结论 通过靶向注射慢病毒载体来上调FoxO1的表达可改善DM大鼠足细胞的损伤.     

足细胞损伤与糖尿病肾病的研究进展

糖尿病肾病是糖尿病的严重并发症,其主要临床特点为尿蛋白排泄率逐年增加、肾功能减退至终末期肾病。近年来,肾小球滤过屏障结构和功能的改变,尤其是作为肾小球滤过屏障结构成分的足细胞在糖尿病肾病发生、发展中的作用,成为研究热点。足细胞是一种终末分化的多突状细胞,足细胞的损伤与蛋白尿的发生、发展密切相关,现通过对常见足细胞损伤的表现,及针对足细胞损伤的机制和治疗予以综述。     

Neonatal Fc receptor stimulation induces ubiquitin c-terminal hydrolase-1 overexpression in podocytes through activation of p38 mitogen-activated protein kinase

Ubiquitin c-terminal hydrolase-1 is overexpressed in renal podocytes in some immune complex-mediated glomerulonephritides, an effect closely related to extensive podocyte injury. Neonatal Fc receptor is newly recognized to be present on human renal podocytes. It is presumed that neonatal Fc receptor serves as a sensor for immune stimulation transduction and is involved in the pathogenesis of podocyte injury. In our current study, we found that neonatal Fc receptor was constitutively expressed in normal podocytes and up-regulated by immune stimulation induced by antithymocyte serum. An increase in neonatal Fc receptor expression was observed in human podocytes within diseased glomeruli in 97 cases of various glomerulonephritides. The expression percentage was significantly higher in immune-mediated disease, including membranous nephropathy (46.7%), immunoglobin A nephropathy (66.7%), lupus nephritis (87.5%), and acute proliferative glomerulonephritis (100%), than in normal kidney samples (16.7%) (P < .05), whereas there was no significant difference between minimal-change disease and normal kidney. Further study showed that neonatal Fc receptor up-regulated the expression of ubiquitin c-terminal hydrolase-1 via activation of p38 in podocytes subjected to immune stimulation in vitro. These data suggest that neonatal Fc receptor acts as an immune sensor that evokes an inflammatory response, which may lead to functional and morphological changes in podocytes in glomerulonephritides.     

肾小球疾病患者尿沉渣足细胞分子podocin和podocalyxin分析

目的：以ELISA法检测尿沉渣足细胞podocin,podocalyxin排泌并观察其与不同肾小球疾病的关系。方法：共收集我院自2010年5月～8月以来行肾活检证实为肾小球疾病的患者,收集其临床资料,并以ELISA法检测尿沉渣足细胞分子podocin,podocalyxin。结果：共40个患者,男15例,女25例,平均年龄（38.27±16.33）岁,增殖性肾小球疾病患者19例：IgA肾病10例,新月体性肾炎2例,IgM肾病2例,Ⅳ（A/G）型狼疮性肾炎5例;非增殖性肾小球疾病患者19例：微小病变型（MCD）5例,局灶节段硬化性肾小球肾炎（FSGS）8例,膜性肾病（MN）6例,另原发性肾淀粉样变性2例,对照健康自愿者10例。尿podocin分子排泌在正常对照组最低,在增殖性肾小球疾病和非增殖性肾小球疾病间差异无统计学意义（P〉0.05）,增殖性肾小球疾病尿podocin排泌高于肾淀粉样变性患者（P〈0.05）。新月体肾炎的尿podocin排泌显著高于其他肾小球疾病（P〈0.05）,后依次FSGS,IgA肾病,狼疮性肾炎,MN,IgM肾病,MCD;尿沉渣podocalyxin排泌在正常对照组最低,而增殖性肾小球肾炎和非增殖性肾小球肾炎间差异无统计学意义（P〉0.05）。新月体肾炎尿podocalyxin排泄量最高,其后依次为FSGS,IgA肾病,MN,狼疮性肾炎,MCD,IgM肾病,以肾淀粉样变性最低。尿podocalyxin与podocin呈正相关,尿podocin与血C3呈负相关。结论：ELISA法检测尿沉渣足细胞分子检测可对肾小球疾病患者的肾病理类型提供参考,以正常人尿podocin,podocalyxin排泌最少,增殖性肾小球疾病和非增殖性肾小球疾病间差异无统计学意义,新月体性肾炎尿沉渣podocin及Podocalyxin高于其他疾病患者,FSGS患者的尿沉渣podocin及Podocalyxin排泌量也较多,肾淀粉样变性患者的尿沉渣podocin及Podocalyxin最低,血清C3与尿podocin的排泌呈负相关。